Journal of Cluster Science最新文献

In this study, an operative technique was presented for the synthesis of the magnetically separable γ-Fe₂O₃@SiO₂@ZIF8@Ag photocatalyst. The synthesized nanostructures were identified using various structural analyses, including XRD, EDX/SEM, FTIR, bandgap, and VSM. Their ability to remove norfloxacin (NOR) was then examined by studying the effects of various parameters, including photocatalyst dose, solution pH, initial NOR concentration, and reaction time. The results showed that the catalyst had the best performance, with an efficiency of 100% under UV light and 96.2%unnder visible light, at a catalyst dose of 0.4 g/L and a reaction time of 45 min. Stability tests also showed that the synthesized photocatalyst maintained its proper performance after five cycles, and its efficiency was reduced by only 4.5%. Also, a comparison between the adsorption and the photocatalytic process showed that the adsorption process removed only 42% of NOR after 60 min, whereas the photocatalytic process, under both visible and UV light irradiation, was able to eliminate 100% of NOR in the same time period. The results showed that the degradation kinetics follow the first-order kinetic model. The reaction rate constants using UV and visible lamps were 0.082 and 0.056 min^− 1, respectively, which indicates the degradation rate for UV light is 1.46 times higher compared to visible light. Also, the half-life times for the process with UV and visible light were 8.4 and 12.3 min, respectively. The average oxidation state (AOS) and carbon oxidation state (COS) of the process increased over time, indicating good degradation of NOR and conversion of non-biodegradable wastewater into biodegradable wastewater. Reactive oxygen species (ROS) assays showed that hydroxyl radicals and holes have the main role in the degradation process. Therefore, the proposed photocatalysts can be considered suitable, cost-effective, and reusable for the treatment of hospital wastewater.

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The optical properties of Carbon dot (CD) solution significantly change on dilution. Herein, the effect of dilution on the optical properties of folic acid-derived CD was meticulously analyzed using absorption and photoluminescence (PL) spectroscopy. Absorption spectra of as-prepared CD solution consist of four overlapping yet discernable absorption bands centered at ~ 249, 302, 348, and 330 nm, respectively, attributed to originate from the π-π^* transition and n-π^* transitions and/or surface states. As the CD solution is diluted from 100 to 5%, these four absorption bands become more resolved. Moreover, we observed a blueshift of ~ 30 nm for the transitions at ~ 302 nm due to surface state with dilution up to 20% CD concentration. This is attributed to the decrease in the interaction between surface states due to the increase in the interparticle distance with dilution. PL emission from the as-prepared CD solution is centered at 463 nm and is asymmetric. This can be resolved into three components centered at 446 nm (intense), 474 nm (intense) and 508 nm (weak) respectively. With dilution, the PL intensity corresponding to the 463 nm emission seems to increase up to an optimum concentration of 15% CD and then decreases. The high concentration effectively quenches the luminescence through inner filter effect which is evident from the overlapping of absorption peak with the peak in the excitation spectrum together with no notable change in the average decay time. The decrease in the percentage of overlapping area of the absorption and excitation spectra with dilution causes the reduction of inner filter effect and enhances the luminescence for diluted solutions. Furthermore, we found that the surface states become more dominant in the contribution of luminescence of CD, whose influence diminishes in extremely diluted solutions, thereby the intensity decrease below 15% dilution.

Nanotechnology is increasingly recognized for its crucial role in addressing challenges in agriculture and environmental management, with nano-scaled materials central to this advancement. Conventional physical and chemical synthesis methods for nanomaterials often involve hazardous chemicals, posing safety and environmental risks, and are frequently cost-ineffective. This review investigates the innovative biosynthesis of magnesium oxide (MgO) nanoparticles, emphasizing their production through eco-friendly approaches involving biomolecules, plant-derived phytoconstituents, polyphenols, bacteria, algae, and fungi. We highlight how biosynthesized MgO nanoparticles exhibit exceptional properties, including unique morphology, high surface area, controlled particle size, and effective stabilization. The review also explores recent advances in their application as nanocatalysts, particularly for environmental remediation tasks such as photocatalytic degradation of dyes and removal of heavy metal ions and pesticides from contaminated environments. By underscoring the significance of green synthesis techniques, this study illustrates their potential in advancing sustainable nanotechnology solutions. It provides a promising foundation for future research in addressing pressing environmental challenges.

Recently, metal and metal oxide nanoparticles have garnered significant scientific interest due to their distinctive properties and promising applications across diverse fields. This study details the successful synthesis and characterization of Fe₃O₄, Ag, and magnetite/silver core-shell (Fe₃O₄/Ag) nanocomposites, prepared through chemical reduction and co-precipitation methods. The successful incorporation of Ag into Fe₃O₄ nanoparticles was confirmed through X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. Physical characterization revealed that the synthesized nanoparticles were small in size and highly pure. Their optical and electrical properties, including bandgap and electrical conductivity, were also characterized. The antibacterial activity of the synthesized Fe₃O₄, Ag, and Fe₃O₄/Ag nanoparticles was evaluated using Minimum Bactericidal Concentration (MBC) against pathogenic bacterial strains: S. typhimurium, P. aeruginosa, and S. aureus. The results demonstrated that Ag, Fe₃O_4, and Fe₃O₄/Ag nanoparticles could inhibit high concentrations of bacteria, indicating an excellent antimicrobial effect. Furthermore, the Fe₃O₄/Ag nanoparticles were found to be more effective than both Fe₃O₄ and Ag nanoparticles in inhibiting the selected pathogenic bacteria strains: S. typhimurium, P. aeruginosa, and S. aureus.

Silica nanoparticles are being studied for enhanced oil recovery (EOR) due to their ease of production and tunable characteristics. However, limited research has explored the impact of nanoparticle morphology on their effectiveness in EOR. This study investigates the synthesis and characterization of silica nanoparticles in two distinct morphologies: spherical and rod-shaped and their adsorption onto carbonate rock surfaces. Various analytical techniques, including FESEM, EDS, FTIR, TGA, BET, and XRD, were employed to characterize the nanoparticles. The study also examined the stability and zeta potential of nanofluids prepared with these nanoparticles in different salt solutions. The results revealed that rod-shaped nanoparticles exhibited greater thermal stability and higher zeta potential than spherical nanoparticles, contributing to the improved stability of the nanofluids. Additionally, the adsorption behavior of the nanoparticles on carbonate rock surfaces was assessed, with rod-shaped nanoparticles showing higher adsorption quantities compared to their spherical counterparts. The adsorption process followed pseudo-second-order kinetics and was influenced by both intraparticle and film diffusion mechanisms. The equilibrium adsorption data for silica nanoparticles was accurately described by the Langmuir isotherm model. Moreover, artificial neural networks (ANN) and least-squares support-vector machines (LSSVM) were utilized to model the adsorption behavior of nanoparticles. The high R² values indicated that these models effectively predicted nanoparticle adsorption on carbonate rock. The study also observed that rod-shaped nanoparticles caused more significant alterations in the roughness of the rock surface than spherical nanoparticles, potentially influencing oil flow in the porous medium during the EOR process.

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In this study, we present a novel green synthesis method for magnesium oxide/magnesium peroxide nanocomposite using citric acid, enhancing both photocatalytic degradation and antioxidant activity. The physical properties and light absorption of the nanostructure were examined using X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, and ultraviolet–visible spectroscopy techniques. A cubic phase was identified, with a nano-size of 25 nm, and a bandgap energy of 2.45 eV was determined. In the photocatalytic degradation tests, the nanostructure achieved an 85% removal rate of Brilliant Cresyl Blue dye after 120 min, with a pseudo-first-order rate constant of 0.014 min⁻¹. Computational simulations revealed a high adsorption energy of -131.552 eV for Brilliant Cresyl Blue on the magnesium oxide/magnesium peroxide nanocomposite, indicating strong binding affinity and supporting the experimental degradation efficiency. Antioxidant assays revealed a half-maximal inhibitory concentration value of 45.81 µg/mL, showcasing substantial free radical scavenging capabilities comparable to established antioxidants. The antibacterial properties of magnesium oxide/magnesium peroxide nanocomposite were assessed against Staphylococcus aureus through the agar well diffusion method. The results demonstrated significant antibacterial efficacy, with inhibition zones ranging from 7.9 ± 0.4 mm to 14.9 ± 1.5 mm, indicating a dose-dependent antibacterial effect. This research advances green synthesis methods for multifunctional nanomaterials, offering promising solutions for environmental remediation and highlighting the potential of magnesium oxide/magnesium peroxide nanocomposite in wastewater treatment, antioxidant applications, and as a potent antibacterial agent.

The COVID-19 pandemic highlighted the urgent need for improved personal protective equipment (PPE). Green-synthesised silver nanoparticles (AgNPs) using pandan (Pandanus amaryllifolius) extract offer a sustainable solution to enhance PPE effectiveness against infectious diseases. This eco-friendly approach utilises pandan’s bioactive compounds to reduce silver ions into nanoparticles, providing a sustainable alternative to conventional chemical synthesis methods. The resulting AgNPs exhibit potent antimicrobial and antiviral properties, making them valuable for incorporation into PPE fabrics and coatings. Beyond antimicrobial benefits, pandan-derived AgNPs may impart natural fragrances and skin-soothing properties, enhancing user comfort. The green synthesis process reduces environmental impact and potential toxicity associated with conventional chemical methods. While challenges in scaling production, ensuring regulatory compliance, and assessing long-term health and environmental effects persist, pandan-derived AgNPs-coated PPE represents an innovative approach to infection prevention. This technology has the potential to significantly improve safety measures in healthcare and other high-risk environments while promoting sustainability.

This study delved on development of curcumin loaded Nanostructured Lipid carrier (NLC) incorporated into gastro-retentive oral in-situ gel for specifically designed to the stomach delivery. Curcumin is less soluble in stomach pH, so a high amount of drug would be required to produce the desired effects. The solubility of curcumin was enhanced by incorporating curcumin into NLC through size reduction. Subsequently, it was formulated into GRDDS for targeted stomach-specific delivery. The curcumin loaded NLC was fabricated using a high shear homogenization technique. Through lipid screening, Precirol ATO 5 and Labrafac PG were chosen as a lipids, and tween 80 was selected as a surfactant in this formulation. A formulation (NLC-F4) comprising 2% lipids and 800 mg of surfactant was chosen as the best formulation, average mean particle size was found to be 119.3 ± 0.13 nm, PDI was found to be 0.127 ± 0.02, Zeta potential was found to be -30 ± 0.17 mV and % of encapsulation efficiency were found to be 83.4 ± 1.5%. FT-IR investigation showed no interactions. Scanning Electron Microscopy (SEM) revealed smooth and spherical shaped particles, while Differential Scanning Calorimetry (DSC) assessment suggested that curcumin is complexed in the NLC formulation. The in vitro drug release of curcumin from NLC-F4 showed 8 times enhanced drug release compared with the pure curcumin in pH 1.2 buffer. In vitro antioxidant and anti-inflammatory studies revealed significant effects compared to reference standards. Drug release kinetics followed first order release and Weibull kinetics models. The curcumin loaded NLC was fabricated into oral in-situ gel to enhances the gastric retention time and prolong release of drug in the stomach. The system exhibited quick gelation time, optimal viscosity, gastric buoyant density, 24 h floating time, good gel strength, and sustained drug release. These investigations revealed that an oral in-situ gelling system containing curcumin loaded NLC has potential as a carrier for stomach specific delivery and could serve as an alternative dosage form compared to conventional ones for treating gastric ulcers in patients.

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This research outlines the development, comprehensive analysis, and assessment of the photocatalytic and antibacterial properties of ZnO/ZnSnO₃ nanocomposite (NC). The nanocomposite was synthesized using an eco-friendly green synthesis method with lemon peel extract. Techniques such as XRD, SEM, and FTIR verified the formation of dual-phase ZnO/ZnSnO₃ NC with an energy gap of ~ 1.9 eV and an average crystallite size of ~ 25.45 ± 1.24 nm. Photocatalytic degradation evaluated for Evans Blue (EB) dye under solar light indicated high degradation efficiency ~ 99.57% during 90 min, following pseudo-first-order kinetics with a rate constant ~ 0.11 min⁻¹. Furthermore, ZnO/ZnSnO₃ NC exhibited notable antibacterial potential with inhibition zones ranging from (10.0 ± 1.3 to 12.0 ± 0.5) mm for E. coli and (9.0 ± 0.8 to 14.0 ± 0.6) mm for P. aeruginosa, with improved activity against K. pneumoniae and S. aureus. The as-prepared NC exhibited significant antifungal activity against C. albicans with inhibition zones ~ 22.0 ± 0.3 mm. The results obtained categorized ZnO/ZnSnO₃ NC as a potential candidate to be utilized for environmental cleanup and wastewater treatment.